1. Field of the Invention
The present invention relates to the field of flat panel displaying, and in particular to a side-edge backlight module.
2. The Related Arts
Liquid crystal displays (LCDs) have a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and are thus of wide applications, such as mobile phones, personal digital assistants (PDAs), digital cameras, computer monitors, and notebook computer screens.
Most of the liquid crystal displays that are currently available in the market are backlighting liquid crystal displays, which comprise an enclosure, a liquid crystal panel arranged in the enclosure, and a backlight module mounted in the enclosure. The structure of a conventional liquid crystal panel is composed of a color filter (CF) substrate, a thin-film transistor (TFT) array substrate, and a liquid crystal layer arranged between the two substrates and the principle of operation is that a driving voltage is applied to the two glass substrates to control rotation of the liquid crystal molecules of the liquid crystal layer in order to refract out light emitting from the backlight module for generating images. Since the liquid crystal panel itself does not emit light, light must be provided from the backlight module in order to normally display images. Thus, the backlight module is one of the key components of the liquid crystal displays. The backlight modules can be classified in two types, namely a side-edge backlight module and a direct backlight module, according to the site where light gets incident. The direct backlight module comprises a light source, such as a cold cathode fluorescent lamp (CCFL) or a light-emitting diode (LED), which is arranged at the backside of the liquid crystal panel to form a planar light source directly supplied to the liquid crystal display panel. The side-edge backlight module comprises an LED light bar, serving as a backlight source, which is arranged at an edge of a backplane to be located rearward of one side of the liquid crystal display panel. The LED light bar emits light that enters a light guide plate (LGP) through a light incident face at one side of the light guide plate and is projected out of a light emergence face of the light guide plate, after being reflected and diffused, to pass through an optic film assembly so as to form a planar light source for the liquid crystal display panel.
Referring to FIG. 1, the side-edge backlight module comprises: a backplane 100, a reflector plate 200 arranged in the backplane 100, a light guide plate 300 arranged on the reflector plate 200, a backlight source 400 arranged in the backplane 100, and a heat dissipation board 500 arranged between the backlight source 400 and the backplane 100. The backplane 100 comprises a bottom board 102 and side boards 104 connected to the bottom board 102. The backlight source 400 is attached via thermal paste (not shown) to the heat dissipation board 500. The heat dissipation board 500 is generally an aluminum board, a copper board, or a graphite patch, which is fixed by screws to the bottom board 102 of the backplane 100. Heat generated by the backlight source 400 is transmitted through the heat dissipation board 500 to the bottom board 102 of the backplane 100 and heat exchange is then performed through the backplane 100 with the surrounding atmosphere to realize heat dissipation. However, the thermal conductivity coefficient of the thermal paste is not great so that the heat dissipation performance of the backlight module is not good and the quality of the backlight module is thus affected.